2 * libudev - interface to udev device information
4 * Copyright (C) 2008-2010 Kay Sievers <kay.sievers@vrfy.org>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
22 #include <sys/param.h>
25 #include "libudev-private.h"
28 * SECTION:libudev-enumerate
29 * @short_description: lookup and sort sys devices
31 * Lookup devices in the sys filesystem, filter devices by properties,
32 * and return a sorted list of devices.
43 * Opaque object representing one device lookup/sort context.
45 struct udev_enumerate {
48 struct udev_list sysattr_match_list;
49 struct udev_list sysattr_nomatch_list;
50 struct udev_list subsystem_match_list;
51 struct udev_list subsystem_nomatch_list;
52 struct udev_list sysname_match_list;
53 struct udev_list properties_match_list;
54 struct udev_list tags_match_list;
55 struct udev_device *parent_match;
56 struct udev_list devices_list;
57 struct syspath *devices;
58 unsigned int devices_cur;
59 unsigned int devices_max;
60 bool devices_uptodate:1;
61 bool match_is_initialized;
66 * @udev: udev library context
68 * Create an enumeration context to scan /sys.
70 * Returns: an enumeration context.
72 _public_ struct udev_enumerate *udev_enumerate_new(struct udev *udev)
74 struct udev_enumerate *udev_enumerate;
76 udev_enumerate = calloc(1, sizeof(struct udev_enumerate));
77 if (udev_enumerate == NULL)
79 udev_enumerate->refcount = 1;
80 udev_enumerate->udev = udev;
81 udev_list_init(udev, &udev_enumerate->sysattr_match_list, false);
82 udev_list_init(udev, &udev_enumerate->sysattr_nomatch_list, false);
83 udev_list_init(udev, &udev_enumerate->subsystem_match_list, true);
84 udev_list_init(udev, &udev_enumerate->subsystem_nomatch_list, true);
85 udev_list_init(udev, &udev_enumerate->sysname_match_list, true);
86 udev_list_init(udev, &udev_enumerate->properties_match_list, false);
87 udev_list_init(udev, &udev_enumerate->tags_match_list, true);
88 udev_list_init(udev, &udev_enumerate->devices_list, false);
89 return udev_enumerate;
94 * @udev_enumerate: context
96 * Take a reference of a enumeration context.
98 * Returns: the passed enumeration context
100 _public_ struct udev_enumerate *udev_enumerate_ref(struct udev_enumerate *udev_enumerate)
102 if (udev_enumerate == NULL)
104 udev_enumerate->refcount++;
105 return udev_enumerate;
109 * udev_enumerate_unref:
110 * @udev_enumerate: context
112 * Drop a reference of an enumeration context. If the refcount reaches zero,
113 * all resources of the enumeration context will be released.
115 * Returns: the passed enumeration context if it has still an active reference, or #NULL otherwise.
117 _public_ struct udev_enumerate *udev_enumerate_unref(struct udev_enumerate *udev_enumerate)
121 if (udev_enumerate == NULL)
123 udev_enumerate->refcount--;
124 if (udev_enumerate->refcount > 0)
125 return udev_enumerate;
126 udev_list_cleanup(&udev_enumerate->sysattr_match_list);
127 udev_list_cleanup(&udev_enumerate->sysattr_nomatch_list);
128 udev_list_cleanup(&udev_enumerate->subsystem_match_list);
129 udev_list_cleanup(&udev_enumerate->subsystem_nomatch_list);
130 udev_list_cleanup(&udev_enumerate->sysname_match_list);
131 udev_list_cleanup(&udev_enumerate->properties_match_list);
132 udev_list_cleanup(&udev_enumerate->tags_match_list);
133 udev_device_unref(udev_enumerate->parent_match);
134 udev_list_cleanup(&udev_enumerate->devices_list);
135 for (i = 0; i < udev_enumerate->devices_cur; i++)
136 free(udev_enumerate->devices[i].syspath);
137 free(udev_enumerate->devices);
138 free(udev_enumerate);
143 * udev_enumerate_get_udev:
144 * @udev_enumerate: context
146 * Get the udev library context.
148 * Returns: a pointer to the context.
150 _public_ struct udev *udev_enumerate_get_udev(struct udev_enumerate *udev_enumerate)
152 if (udev_enumerate == NULL)
154 return udev_enumerate->udev;
157 static int syspath_add(struct udev_enumerate *udev_enumerate, const char *syspath)
160 struct syspath *entry;
162 /* double array size if needed */
163 if (udev_enumerate->devices_cur >= udev_enumerate->devices_max) {
167 add = udev_enumerate->devices_max;
170 buf = realloc(udev_enumerate->devices, (udev_enumerate->devices_max + add) * sizeof(struct syspath));
173 udev_enumerate->devices = buf;
174 udev_enumerate->devices_max += add;
177 path = strdup(syspath);
180 entry = &udev_enumerate->devices[udev_enumerate->devices_cur];
181 entry->syspath = path;
182 entry->len = strlen(path);
183 udev_enumerate->devices_cur++;
184 udev_enumerate->devices_uptodate = false;
188 static int syspath_cmp(const void *p1, const void *p2)
190 const struct syspath *path1 = p1;
191 const struct syspath *path2 = p2;
195 len = MIN(path1->len, path2->len);
196 ret = memcmp(path1->syspath, path2->syspath, len);
198 if (path1->len < path2->len)
200 else if (path1->len > path2->len)
206 /* For devices that should be moved to the absolute end of the list */
207 static bool devices_delay_end(struct udev *udev, const char *syspath)
209 static const char *delay_device_list[] = {
216 for (i = 0; delay_device_list[i] != NULL; i++) {
217 if (strstr(syspath + strlen("/sys"), delay_device_list[i]) != NULL)
223 /* For devices that should just be moved a little bit later, just
224 * before the point where some common path prefix changes. Returns the
225 * number of characters that make up that common prefix */
226 static size_t devices_delay_later(struct udev *udev, const char *syspath)
230 /* For sound cards the control device must be enumerated last
231 * to make sure it's the final device node that gets ACLs
232 * applied. Applications rely on this fact and use ACL changes
233 * on the control node as an indicator that the ACL change of
234 * the entire sound card completed. The kernel makes this
235 * guarantee when creating those devices, and hence we should
236 * too when enumerating them. */
238 if ((c = strstr(syspath, "/sound/card"))) {
240 c += strcspn(c, "/");
242 if (startswith(c, "/controlC"))
243 return c - syspath + 1;
250 * udev_enumerate_get_list_entry:
251 * @udev_enumerate: context
253 * Get the first entry of the sorted list of device paths.
255 * Returns: a udev_list_entry.
257 _public_ struct udev_list_entry *udev_enumerate_get_list_entry(struct udev_enumerate *udev_enumerate)
259 if (udev_enumerate == NULL)
261 if (!udev_enumerate->devices_uptodate) {
264 struct syspath *prev = NULL, *move_later = NULL;
265 size_t move_later_prefix = 0;
267 udev_list_cleanup(&udev_enumerate->devices_list);
268 qsort(udev_enumerate->devices, udev_enumerate->devices_cur, sizeof(struct syspath), syspath_cmp);
270 max = udev_enumerate->devices_cur;
271 for (i = 0; i < max; i++) {
272 struct syspath *entry = &udev_enumerate->devices[i];
274 /* skip duplicated entries */
276 entry->len == prev->len &&
277 memcmp(entry->syspath, prev->syspath, entry->len) == 0)
281 /* skip to be delayed devices, and add them to the end of the list */
282 if (devices_delay_end(udev_enumerate->udev, entry->syspath)) {
283 syspath_add(udev_enumerate, entry->syspath);
284 /* need to update prev here for the case realloc() gives a different address */
285 prev = &udev_enumerate->devices[i];
289 /* skip to be delayed devices, and move the to
290 * the point where the prefix changes. We can
291 * only move one item at a time. */
293 move_later_prefix = devices_delay_later(udev_enumerate->udev, entry->syspath);
295 if (move_later_prefix > 0) {
302 strncmp(entry->syspath, move_later->syspath, move_later_prefix) != 0) {
304 udev_list_entry_add(&udev_enumerate->devices_list, move_later->syspath, NULL);
308 udev_list_entry_add(&udev_enumerate->devices_list, entry->syspath, NULL);
312 udev_list_entry_add(&udev_enumerate->devices_list, move_later->syspath, NULL);
314 /* add and cleanup delayed devices from end of list */
315 for (i = max; i < udev_enumerate->devices_cur; i++) {
316 struct syspath *entry = &udev_enumerate->devices[i];
318 udev_list_entry_add(&udev_enumerate->devices_list, entry->syspath, NULL);
319 free(entry->syspath);
321 udev_enumerate->devices_cur = max;
323 udev_enumerate->devices_uptodate = true;
325 return udev_list_get_entry(&udev_enumerate->devices_list);
329 * udev_enumerate_add_match_subsystem:
330 * @udev_enumerate: context
331 * @subsystem: filter for a subsystem of the device to include in the list
333 * Match only devices belonging to a certain kernel subsystem.
335 * Returns: 0 on success, otherwise a negative error value.
337 _public_ int udev_enumerate_add_match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
339 if (udev_enumerate == NULL)
341 if (subsystem == NULL)
343 if (udev_list_entry_add(&udev_enumerate->subsystem_match_list, subsystem, NULL) == NULL)
349 * udev_enumerate_add_nomatch_subsystem:
350 * @udev_enumerate: context
351 * @subsystem: filter for a subsystem of the device to exclude from the list
353 * Match only devices not belonging to a certain kernel subsystem.
355 * Returns: 0 on success, otherwise a negative error value.
357 _public_ int udev_enumerate_add_nomatch_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
359 if (udev_enumerate == NULL)
361 if (subsystem == NULL)
363 if (udev_list_entry_add(&udev_enumerate->subsystem_nomatch_list, subsystem, NULL) == NULL)
369 * udev_enumerate_add_match_sysattr:
370 * @udev_enumerate: context
371 * @sysattr: filter for a sys attribute at the device to include in the list
372 * @value: optional value of the sys attribute
374 * Match only devices with a certain /sys device attribute.
376 * Returns: 0 on success, otherwise a negative error value.
378 _public_ int udev_enumerate_add_match_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
380 if (udev_enumerate == NULL)
384 if (udev_list_entry_add(&udev_enumerate->sysattr_match_list, sysattr, value) == NULL)
390 * udev_enumerate_add_nomatch_sysattr:
391 * @udev_enumerate: context
392 * @sysattr: filter for a sys attribute at the device to exclude from the list
393 * @value: optional value of the sys attribute
395 * Match only devices not having a certain /sys device attribute.
397 * Returns: 0 on success, otherwise a negative error value.
399 _public_ int udev_enumerate_add_nomatch_sysattr(struct udev_enumerate *udev_enumerate, const char *sysattr, const char *value)
401 if (udev_enumerate == NULL)
405 if (udev_list_entry_add(&udev_enumerate->sysattr_nomatch_list, sysattr, value) == NULL)
410 static int match_sysattr_value(struct udev_device *dev, const char *sysattr, const char *match_val)
412 const char *val = NULL;
415 val = udev_device_get_sysattr_value(dev, sysattr);
418 if (match_val == NULL) {
422 if (fnmatch(match_val, val, 0) == 0) {
431 * udev_enumerate_add_match_property:
432 * @udev_enumerate: context
433 * @property: filter for a property of the device to include in the list
434 * @value: value of the property
436 * Match only devices with a certain property.
438 * Returns: 0 on success, otherwise a negative error value.
440 _public_ int udev_enumerate_add_match_property(struct udev_enumerate *udev_enumerate, const char *property, const char *value)
442 if (udev_enumerate == NULL)
444 if (property == NULL)
446 if (udev_list_entry_add(&udev_enumerate->properties_match_list, property, value) == NULL)
452 * udev_enumerate_add_match_tag:
453 * @udev_enumerate: context
454 * @tag: filter for a tag of the device to include in the list
456 * Match only devices with a certain tag.
458 * Returns: 0 on success, otherwise a negative error value.
460 _public_ int udev_enumerate_add_match_tag(struct udev_enumerate *udev_enumerate, const char *tag)
462 if (udev_enumerate == NULL)
466 if (udev_list_entry_add(&udev_enumerate->tags_match_list, tag, NULL) == NULL)
472 * udev_enumerate_add_match_parent:
473 * @udev_enumerate: context
474 * @parent: parent device where to start searching
476 * Return the devices on the subtree of one given device. The parent
477 * itself is included in the list.
479 * A reference for the device is held until the udev_enumerate context
482 * Returns: 0 on success, otherwise a negative error value.
484 _public_ int udev_enumerate_add_match_parent(struct udev_enumerate *udev_enumerate, struct udev_device *parent)
486 if (udev_enumerate == NULL)
490 if (udev_enumerate->parent_match != NULL)
491 udev_device_unref(udev_enumerate->parent_match);
492 udev_enumerate->parent_match = udev_device_ref(parent);
497 * udev_enumerate_add_match_is_initialized:
498 * @udev_enumerate: context
500 * Match only devices which udev has set up already. This makes
501 * sure, that the device node permissions and context are properly set
502 * and that network devices are fully renamed.
504 * Usually, devices which are found in the kernel but not already
505 * handled by udev, have still pending events. Services should subscribe
506 * to monitor events and wait for these devices to become ready, instead
507 * of using uninitialized devices.
509 * For now, this will not affect devices which do not have a device node
510 * and are not network interfaces.
512 * Returns: 0 on success, otherwise a negative error value.
514 _public_ int udev_enumerate_add_match_is_initialized(struct udev_enumerate *udev_enumerate)
516 if (udev_enumerate == NULL)
518 udev_enumerate->match_is_initialized = true;
523 * udev_enumerate_add_match_sysname:
524 * @udev_enumerate: context
525 * @sysname: filter for the name of the device to include in the list
527 * Match only devices with a given /sys device name.
529 * Returns: 0 on success, otherwise a negative error value.
531 _public_ int udev_enumerate_add_match_sysname(struct udev_enumerate *udev_enumerate, const char *sysname)
533 if (udev_enumerate == NULL)
537 if (udev_list_entry_add(&udev_enumerate->sysname_match_list, sysname, NULL) == NULL)
542 static bool match_sysattr(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
544 struct udev_list_entry *list_entry;
547 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_nomatch_list)) {
548 if (match_sysattr_value(dev, udev_list_entry_get_name(list_entry),
549 udev_list_entry_get_value(list_entry)))
553 if (udev_list_get_entry(&udev_enumerate->sysattr_match_list) != NULL) {
554 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysattr_match_list)) {
555 /* anything that does not match, will make it FALSE */
556 if (!match_sysattr_value(dev, udev_list_entry_get_name(list_entry),
557 udev_list_entry_get_value(list_entry)))
565 static bool match_property(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
567 struct udev_list_entry *list_entry;
570 /* no match always matches */
571 if (udev_list_get_entry(&udev_enumerate->properties_match_list) == NULL)
574 /* loop over matches */
575 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->properties_match_list)) {
576 const char *match_key = udev_list_entry_get_name(list_entry);
577 const char *match_value = udev_list_entry_get_value(list_entry);
578 struct udev_list_entry *property_entry;
580 /* loop over device properties */
581 udev_list_entry_foreach(property_entry, udev_device_get_properties_list_entry(dev)) {
582 const char *dev_key = udev_list_entry_get_name(property_entry);
583 const char *dev_value = udev_list_entry_get_value(property_entry);
585 if (fnmatch(match_key, dev_key, 0) != 0)
587 if (match_value == NULL && dev_value == NULL) {
591 if (match_value == NULL || dev_value == NULL)
593 if (fnmatch(match_value, dev_value, 0) == 0) {
603 static bool match_tag(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
605 struct udev_list_entry *list_entry;
607 /* no match always matches */
608 if (udev_list_get_entry(&udev_enumerate->tags_match_list) == NULL)
611 /* loop over matches */
612 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->tags_match_list))
613 if (!udev_device_has_tag(dev, udev_list_entry_get_name(list_entry)))
619 static bool match_parent(struct udev_enumerate *udev_enumerate, struct udev_device *dev)
621 if (udev_enumerate->parent_match == NULL)
624 return startswith(udev_device_get_devpath(dev), udev_device_get_devpath(udev_enumerate->parent_match));
627 static bool match_sysname(struct udev_enumerate *udev_enumerate, const char *sysname)
629 struct udev_list_entry *list_entry;
631 if (udev_list_get_entry(&udev_enumerate->sysname_match_list) == NULL)
634 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->sysname_match_list)) {
635 if (fnmatch(udev_list_entry_get_name(list_entry), sysname, 0) != 0)
642 static int scan_dir_and_add_devices(struct udev_enumerate *udev_enumerate,
643 const char *basedir, const char *subdir1, const char *subdir2)
645 char path[UTIL_PATH_SIZE];
652 l = util_strpcpyl(&s, sizeof(path), "/sys/", basedir, NULL);
654 l = util_strpcpyl(&s, l, "/", subdir1, NULL);
656 util_strpcpyl(&s, l, "/", subdir2, NULL);
660 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
661 char syspath[UTIL_PATH_SIZE];
662 struct udev_device *dev;
664 if (dent->d_name[0] == '.')
667 if (!match_sysname(udev_enumerate, dent->d_name))
670 util_strscpyl(syspath, sizeof(syspath), path, "/", dent->d_name, NULL);
671 dev = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
675 if (udev_enumerate->match_is_initialized) {
677 * All devices with a device node or network interfaces
678 * possibly need udev to adjust the device node permission
679 * or context, or rename the interface before it can be
680 * reliably used from other processes.
682 * For now, we can only check these types of devices, we
683 * might not store a database, and have no way to find out
684 * for all other types of devices.
686 if (!udev_device_get_is_initialized(dev) &&
687 (major(udev_device_get_devnum(dev)) > 0 || udev_device_get_ifindex(dev) > 0))
690 if (!match_parent(udev_enumerate, dev))
692 if (!match_tag(udev_enumerate, dev))
694 if (!match_property(udev_enumerate, dev))
696 if (!match_sysattr(udev_enumerate, dev))
699 syspath_add(udev_enumerate, udev_device_get_syspath(dev));
701 udev_device_unref(dev);
707 static bool match_subsystem(struct udev_enumerate *udev_enumerate, const char *subsystem)
709 struct udev_list_entry *list_entry;
711 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_nomatch_list)) {
712 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
715 if (udev_list_get_entry(&udev_enumerate->subsystem_match_list) != NULL) {
716 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->subsystem_match_list)) {
717 if (fnmatch(udev_list_entry_get_name(list_entry), subsystem, 0) == 0)
725 static int scan_dir(struct udev_enumerate *udev_enumerate, const char *basedir, const char *subdir, const char *subsystem)
727 char path[UTIL_PATH_SIZE];
731 util_strscpyl(path, sizeof(path), "/sys/", basedir, NULL);
735 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
736 if (dent->d_name[0] == '.')
738 if (!match_subsystem(udev_enumerate, subsystem != NULL ? subsystem : dent->d_name))
740 scan_dir_and_add_devices(udev_enumerate, basedir, dent->d_name, subdir);
747 * udev_enumerate_add_syspath:
748 * @udev_enumerate: context
749 * @syspath: path of a device
751 * Add a device to the list of devices, to retrieve it back sorted in dependency order.
753 * Returns: 0 on success, otherwise a negative error value.
755 _public_ int udev_enumerate_add_syspath(struct udev_enumerate *udev_enumerate, const char *syspath)
757 struct udev_device *udev_device;
759 if (udev_enumerate == NULL)
763 /* resolve to real syspath */
764 udev_device = udev_device_new_from_syspath(udev_enumerate->udev, syspath);
765 if (udev_device == NULL)
767 syspath_add(udev_enumerate, udev_device_get_syspath(udev_device));
768 udev_device_unref(udev_device);
772 static int scan_devices_tags(struct udev_enumerate *udev_enumerate)
774 struct udev_list_entry *list_entry;
776 /* scan only tagged devices, use tags reverse-index, instead of searching all devices in /sys */
777 udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_enumerate->tags_match_list)) {
780 char path[UTIL_PATH_SIZE];
782 util_strscpyl(path, sizeof(path), "/run/udev/tags/", udev_list_entry_get_name(list_entry), NULL);
786 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
787 struct udev_device *dev;
789 if (dent->d_name[0] == '.')
792 dev = udev_device_new_from_id_filename(udev_enumerate->udev, dent->d_name);
796 if (!match_subsystem(udev_enumerate, udev_device_get_subsystem(dev)))
798 if (!match_sysname(udev_enumerate, udev_device_get_sysname(dev)))
800 if (!match_parent(udev_enumerate, dev))
802 if (!match_property(udev_enumerate, dev))
804 if (!match_sysattr(udev_enumerate, dev))
807 syspath_add(udev_enumerate, udev_device_get_syspath(dev));
809 udev_device_unref(dev);
816 static int parent_add_child(struct udev_enumerate *enumerate, const char *path)
818 struct udev_device *dev;
820 dev = udev_device_new_from_syspath(enumerate->udev, path);
824 if (!match_subsystem(enumerate, udev_device_get_subsystem(dev)))
826 if (!match_sysname(enumerate, udev_device_get_sysname(dev)))
828 if (!match_property(enumerate, dev))
830 if (!match_sysattr(enumerate, dev))
833 syspath_add(enumerate, udev_device_get_syspath(dev));
834 udev_device_unref(dev);
838 static int parent_crawl_children(struct udev_enumerate *enumerate, const char *path, int maxdepth)
847 for (dent = readdir(d); dent != NULL; dent = readdir(d)) {
850 if (dent->d_name[0] == '.')
852 if (dent->d_type != DT_DIR)
854 if (asprintf(&child, "%s/%s", path, dent->d_name) < 0)
856 parent_add_child(enumerate, child);
858 parent_crawl_children(enumerate, child, maxdepth-1);
866 static int scan_devices_children(struct udev_enumerate *enumerate)
870 path = udev_device_get_syspath(enumerate->parent_match);
871 parent_add_child(enumerate, path);
872 return parent_crawl_children(enumerate, path, 256);
875 static int scan_devices_all(struct udev_enumerate *udev_enumerate)
879 if (stat("/sys/subsystem", &statbuf) == 0) {
880 /* we have /subsystem/, forget all the old stuff */
881 scan_dir(udev_enumerate, "subsystem", "devices", NULL);
883 scan_dir(udev_enumerate, "bus", "devices", NULL);
884 scan_dir(udev_enumerate, "class", NULL, NULL);
890 * udev_enumerate_scan_devices:
891 * @udev_enumerate: udev enumeration context
893 * Scan /sys for all devices which match the given filters. No matches
894 * will return all currently available devices.
896 * Returns: 0 on success, otherwise a negative error value.
898 _public_ int udev_enumerate_scan_devices(struct udev_enumerate *udev_enumerate)
900 if (udev_enumerate == NULL)
903 /* efficiently lookup tags only, we maintain a reverse-index */
904 if (udev_list_get_entry(&udev_enumerate->tags_match_list) != NULL)
905 return scan_devices_tags(udev_enumerate);
907 /* walk the subtree of one parent device only */
908 if (udev_enumerate->parent_match != NULL)
909 return scan_devices_children(udev_enumerate);
911 /* scan devices of all subsystems */
912 return scan_devices_all(udev_enumerate);
916 * udev_enumerate_scan_subsystems:
917 * @udev_enumerate: udev enumeration context
919 * Scan /sys for all kernel subsystems, including buses, classes, drivers.
921 * Returns: 0 on success, otherwise a negative error value.
923 _public_ int udev_enumerate_scan_subsystems(struct udev_enumerate *udev_enumerate)
926 const char *subsysdir;
928 if (udev_enumerate == NULL)
931 /* all kernel modules */
932 if (match_subsystem(udev_enumerate, "module"))
933 scan_dir_and_add_devices(udev_enumerate, "module", NULL, NULL);
935 if (stat("/sys/subsystem", &statbuf) == 0)
936 subsysdir = "subsystem";
940 /* all subsystems (only buses support coldplug) */
941 if (match_subsystem(udev_enumerate, "subsystem"))
942 scan_dir_and_add_devices(udev_enumerate, subsysdir, NULL, NULL);
944 /* all subsystem drivers */
945 if (match_subsystem(udev_enumerate, "drivers"))
946 scan_dir(udev_enumerate, subsysdir, "drivers", "drivers");